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4. TROUBLE SHOOTING
LGE Internal Use Only
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4.7 Power ON Troubleshooting
Power On sequence of CT815 is :
END key press
→
KPD_PWR_N go to low(VA607), PM7540 KPDPWR_N pin(C12)
→
PM7540 Power Up
→
VMSMC1_1.2V(C437), VMSMC2_1.2V(C438), VMSME_1.8V(C439),
VMSMP_2.6V(C440), VMSMA_2.6V(C457), VTCXO_2.85V(C461) power up and system
reset assert to MSM
→
Phone booting and PS_HOLD(D407) assert to PMIC.
Start
Battery volt age. higher
than 3.20V?
VA707 h igh to low
when key press?
VMSMC1_1.2V, VMSMC2_1.2V,
VMSMP_2.6V, VMSME_1.8V,
VTCXO_2.85V, VMSMA_2.6V power up?
Is clock ok ?
R420 : 19.2M
X401 : 32.768Khz
Check an U202 SMT status
by X-ray
Exc hange U202 o r
Change the Main board
And Retest
Change or charging the
Battery
Check the Key Dome
Change the Main board
Check the TXCO
NO
YES
YES
YES
YES
NO
NO
NO
Summary of Contents for CT815
Page 1: ...Date May 2009 Issue 1 0 Service Manual Model CT815 Service Manual CT815 Internal Use Only ...
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